If you want to get the current \$(x,y)\$ for a given \$t_1\$, what you need to do is initialize the simulation for \$t = 0\$ and do small dt updates until \$t = t_1\$

If you already calculated \$(x,y)\$ for a \$t_1\$ and you want to know their values for a \$t_2\$ where \$t_1 \lt t_2\$, all you need to do is calculating those small dt update steps from \$t_1\$ to \$t_2\$

\$\begingroup\$Thank you so much for this, i'll try it out an get back to you.\$\endgroup\$
– SmithApr 15 '11 at 7:47

\$\begingroup\$from these equations you provided, i'd like to get the current X & Y for a give time (t), should i replace my Vo with V_x and Vo with v_y? Also if i need to add the initial KE with which the ball was fired, will this KE=0.5*m*(V*V) be valid?\$\endgroup\$
– SmithApr 15 '11 at 8:28